... bacteria, stink,weat, etc; 3,display the calendar. Sell air tester PWJ-5P1,newest calendar desigen:display year, ... take a breath or leave the room harmful gas: 0-99 0-30(green light) represent ... (red light) represent high harmful gases5, when harmful gas display light is red, it will alarm, remind ... , sweat, etc. VOC is test the organic volatic gas in the air, mainly tolunene, xylene etc(home decoration ...